protected Map<String, String> makeEmptyMap() {
    Map<String, Integer> underlying = Maps.newHashMap();
    return transformValues(
        new UnmodifiableIteratorMap<String, Integer>(underlying), Functions.toStringFunction());
  }

  @Override
  protected Map<String, String> makePopulatedMap() {
    Map<String, Integer> underlying = Maps.newHashMap();
    underlying.put("a", 1);
    underlying.put("b", 2);

  @Override
  protected Map<String, String> makeEmptyMap() {
    return transformValues(Maps.<String, String>newHashMap(), Functions.<String>identity());
  }

  @Override
  protected Map<String, String> makePopulatedMap() {
    Map<String, Integer> underlying = Maps.newHashMap();
    underlying.put("a", 1);
    underlying.put("b", 2);
    underlying.put("c", 3);

    assertTrue(
        "A Map should equal any other Map containing the same entries.",
        getMap().equals(newHashMap(getSampleEntries())));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  public void testEquals_otherMapWithDifferentEntries() {
    Map<K, V> other = newHashMap(getSampleEntries(getNumEntries() - 1));
    other.put(k3(), v3());
    assertFalse(

    Map<String, Integer> underlying = Maps.newHashMap();
    underlying.put("a", 1);
    Map<String, String> map = transformValues(underlying, Functions.toStringFunction());
    assertEquals("1", map.remove("a"));
    assertNull(map.remove("b"));
  }

  public void testTransformEqualityOfMapsWithNullValues() {
    Map<String, @Nullable String> underlying = Maps.newHashMap();
    underlying.put("a", null);

  @Override
  protected Map<String, String> makeEmptyMap() {
    return transformValues(Maps.<String, String>newHashMap(), Functions.<String>identity());
  }

  @Override
  protected Map<String, String> makePopulatedMap() {
    Map<String, Integer> underlying = Maps.newHashMap();
    underlying.put("a", 1);
    underlying.put("b", 2);
    underlying.put("c", 3);

          assertNull(expected);
        }
      }
    }
  }

  public void testAllRangesAlone() {
    for (Range<Integer> range : RANGES) {
      Map<Integer, Integer> model = Maps.newHashMap();
      putModel(model, range, 1);
      RangeMap<Integer, Integer> test = TreeRangeMap.create();
      test.put(range, 1);
      verify(model, test);
    }
  }

  public void testAllRangePairs() {

  public void testForMapSerialization() {
    Map<String, Integer> map = Maps.newHashMap();
    map.put("foo", 1);
    map.put("bar", 2);
    Multimap<String, Integer> multimapView = Multimaps.forMap(map);
    SerializableTester.reserializeAndAssert(multimapView);
  }

  public void testForMapRemoveAll() {
    Map<String, Integer> map = Maps.newHashMap();
    map.put("foo", 1);
    map.put("bar", 2);
    map.put("cow", 3);

    for (LoadingCache<Object, Object> cache : caches()) {
      Set<Object> keys = cache.asMap().keySet();
      List<Entry<Object, Object>> warmed = warmUp(cache);

      Set<Object> expected = Maps.newHashMap(cache.asMap()).keySet();
      assertThat(keys).containsExactlyElementsIn(expected);
      assertThat(keys.toArray()).asList().containsExactlyElementsIn(expected);

    for (LoadingCache<Object, Object> cache : caches()) {
      Set<Object> keys = cache.asMap().keySet();
      List<Entry<Object, Object>> warmed = warmUp(cache);

      Set<Object> expected = Maps.newHashMap(cache.asMap()).keySet();
      assertThat(keys).containsExactlyElementsIn(expected);
      assertThat(keys.toArray()).asList().containsExactlyElementsIn(expected);

    }
  }

  @CollectionSize.Require(SEVERAL)
  public void testEquals() {
    resetContainer(mapEntry(k0(), v0()), mapEntry(k1(), v0()), mapEntry(k0(), v3()));
    Map<K, Collection<V>> expected = Maps.newHashMap();
    expected.put(k0(), Lists.newArrayList(v0(), v3()));
    expected.put(k1(), Lists.newArrayList(v0()));
    new EqualsTester().addEqualityGroup(expected, multimap().asMap()).testEquals();
  }